Pipe flaring tool

ABSTRACT

A PIPE FLARING TOOL IN WHICH THE PIPE TO BE FLARED IS SOLIDLY GRIPPED AGAINST AN INTERNAL ARBOR OR MANDREL WHILE THE FLARING IS ACCOMPLISHED BY A SPINNING TOOL JOURNALED IN THE MANDREL AND ROTATED ABOUT THE AXIS OF THE PIPE WHILE THE ANGLE OF CONTACT OF THE SPINNING TOOL IS PROGRESSIVELY INCREASED. IN THE CASE OF PLASTIC PIPE SUCH AS POLYBUTYLENE, POLYETHYLENE, POLYVINYL, ETC., USED FOR DOMESTIC WATER SERVICE, THE ANGLE OF THE SPINNING TOOL AT THE END OF THE FLARING OPERATION IS SUBSTANTIALLY 90* AND WHEN THE TOOL IS REMOVED, THE FLARE SPRINGS BACK TO AN ANGLE OF SUBSTANTIALLY 45* SO AS TO FIT A STANDARD COMPRESSION FITTING.

June 22, 1971 5, BJALME 3,585,687

PIPE FLARING TOOL Filed Feb. 4, 1969 INVENTOR E 4 7 BY W W United States Patent Office 3,585,687 PIPE FLARING TOOL Bengt G. Bjalme, Erie, Pa., assignor to Reed Manufacturing Company, Erie, Pa. Filed Feb. 4, 1969, Ser. No. 796,518 Int. Cl. B29c 17/00 US. Cl. 1819TE 15 Claims ABSTRACT OF THE DISCLOSURE A pipe flaring tool in which the pipe to be flared is solidly gripped against an internal arbor or mandrel while the flaring is accomplished by a spinning tool journaled in the mandrel and rotated about the axis of the pipe while the angle of contact of the spinning tool is progressively increased. In the case of plastic pipe such as polybutylene, polyethylene, polyvinyl, etc., used for domestic water service, the angle of the spinning tool at the end of the flaring operation is substantially 90 and when the tool is removed, the flare springs back to an angle of substantially 45 so as to fit a standard compression fitting.

In a preferred form, this invention is intended to flare plastic pipe or tubing such as used for water service. The flaring is effected by a spinning tool journaled in an internal mandrel or arbor anchored in the bore of the pipe and pivoted so that at the start of the spinning operation the tool contacts the projecting end of the pipe at an acute angle which is progressively increased to substantially 90 as the tool sweeps around the pipe end. The local heating due to friction at the areas of contact with the spinning tool is elfective in causing the plastic to flow. The strength of the flare is greater than the strength of the pipe.

In the drawings, FIG. 1 is a side elevation, partly in section, showing the tool inserted in a pipe end in readiness for a flaring operation; FIG. 2 is a section on line 2-2 of FIG. 1; FIG. 3 is a fragmentary view showing the position of the flaring tool midway in the flaring operation; FIG. 4 is a sectional view similar to FIG. 3 showing the position of the tool at the end of the flaring operation; and FIG. 5 is a section through a pipe end flared with the tool and installed in a standard compression flare fitting.

The particular tool illustrated is intended to produce a flared end 1 on a pipe 2 of plastic such as polybutylene, polyethylene, poly-vinyl, etc. Such plastic pipe is diflicult to flare because the plastic resists flowing and tends to return to its initial unflared shape by reason of its memory. The flared end is required for the standard compression type fitting comprising an inner member 3 and an outer member 4.. The outer member is in the form of a nut screwed onto threads 5 on the inner member. As the fitting is tightened, the flared end is squeezed between complernentary tapered surfaces 6 and 7 respectively on the inner and outer members. The inner member 3 has a threaded projection 8 for connection to a water service line. The fitting described is standard for copper tubing for which the plastic tubing 2 is a replacement.

The tool shown in FIGS. 1-4 inclusive is duplex or double ended, one end being used to produce a flare on one size of pipe and the other end to produce a flare on another size of pipe. Corresponding parts on the other end will be indicated by the reference numerals for one end with the subscript a. The tool comprises a crank arm 9 having a slotted end 10 to receive a tongue 11 on a pin 12 and pivoted to the tongue by a pin 13. The pin 13 hinges or pivots the arm 9 for movement about an axis transverse to the axis of the pipe. At the opposite 3,585,687 Patented June 22., 1971 end, the crank arm has a slotted end 10a to receive a tongue 11a on a pin 12a and pivoted to the ears 11a by a pin 13a. The crank arm can be pivoted between positions in line with the pins 12 and 12a to positions substantially at right angles to the pins 12 and 12a. The pin 12 is journaled in a cylindrical plug 14 having a sliding fit in the bore of the pipe or tubing 2 to be flared. The pin 12a is similarly journaled in a plug 14a received in the bore of a pipe of different size. The plug 14 has an external groove 15 receiving an expansible split ring 16 which in its unstressed condition is sufficiently larger than the bore of the pipe 2 so that it always provides a friction grip tending to hold the plug in place even though the pipe is over or under size. The plug is confined between a head 17 and a retaining washer 18 on the pin 12. In order to insure the proper size of flare, the plug is inserted in the bore of the pipe until the end 19 of the pipe is opposite a. groove or gage mark 20 in the arm of rod 9. This provides the proper amount of free or unsupported pipe end projecting beyond the annular stop surface 21 on the plug 14. When the plug is adjusted to this position, clamping jaws 22 and 23 are tightened against the outside of the pipe, clamping the pipe between the jaws and the plug and rigidly supporting the pipe behind the annular stop surface 21. The jaws 22 and 23 are conveniently attached to the stationary and movable jaw members 24 and 25 of a toggle wrench or vise grip pliers 26. This permits quick clamping and unclamping and ready adjustment by means of screw 27 for variations in the wall thickness or diameter of the pipe.

At the start of the flaring operation, the rod 9 is pivoted about pin 13 bringing the external surface of a spinning member 28 into initial contact with the end 19 of the pipe at an acute angle to the axi of the pipe. The spinning member 28 is preferably made as a separate part fixed to the rod by a pin 29 so that it may be readily replaced if necessary. The spinning member is preferably of circular radial cross section and of concave axial cross section so the diameter of the member increases with the distance from its pivot. The rod 9 is then rotated, using the plug 14a at the opposite end as a crank handle while continually exerting an axial pressure tending to increase the angle between the crank arm 9 and the axis of the plug 14. This causes the spinning tool to sweep about the axis of the pipe and to exert a local flaring pressure on the pipe end. When the tube is half way flared, the arm 9 is in the position shown in FIG. 3 where the partially flared end 30 is in contact with an outwardly flaring or concave surface 31 which tends to curl the rim 32 of the flare. The curved or outwardly flaring surface 31 produces an improved flare over that obtained by a straight cylindrical surface on the spinning tool 28 such as indicated by dotted lines 33. While the outwardly flaring surface 31 is preferable, the straight cylindrical surface 33 produces an acceptable flare. At the end of the flarin operation, the flaring tool 28 is in contact with the annular stop surface 21. This limits the position of the crank arm 9 to substantially to the axis of the pipe. At the bottom of FIG. 4, the curl 34 indicates a slight over flaring. At the top of FIG. 4, the flare is shown in its final position after the spring back of the plastic from the over flared condition. This results in a finished flare which will fit the standard compression fitting.

The tool at the opposite end of the crank arm 9 where the parts are designated by the same reference numerals with the subscript a, has the same mode of operation for smaller pipe. In addition to the advantage of being able to flare two sizes of pipe with a single tool, in each case, the plug at the free end of the crank arm serves as a crank handle for rotating the spinning tool about the axis of the pipe in order to produce the flare.

3 The flare can be readily adjusted by the depth of insertion of the plug into the pipe to be flared. This permits adjustment of the tool to the properties of various plastics.

At the end of the flaring operation, the flare will be slightly warm. This indicates that there is a localized heating at the point of contact of the spinning tool with the pipe end which causes local flowing of the pipe end and produces a sort of permanent set which reduces the amount of spring back at the end of the flaring operation. The flares produced by this tool are stronger than the pipe. In the previous flaring tools used for plastic pipe, after assembly into a compression fitting as shown in FIG. 5, stress on the pipe always caused breaking at the flare. With the flare produced by the tool of this ap plication, stress on the pipe produces breakage in the pipe itself rather than in the flare. Not only is the flare produced by the tool stronger than previous flares, but the power required to produce a flare is very slight compared to the power requirements for previous flaring tools.

Because the wall of the pipe adjacent the end being flared is securely clamped between the internal arbor or plug 14 and the external clamp 22, 23, the flares produced by the tool are very uniform. The action of the spinning tool is confined to the unsupported projecting end of the pipe.

The tool is adapted to produce flares on all sizes of plastic pipe and for all standard compression fittings. No special fittings are required.

What is claimed is:

1. A pipe flaring tool comprising arbor means adapted to be received in the bore of a pipe adjacent the pipe end to be flared, means engaging the external surface of the pipe opposite the arbor means and cooperating with the arbor means to clamp the intervening pipe wall therebetween while leaving the pipe end to be flared free, shaft means journaled in the arbor means for rotation relative to the pipe on its axis, a spinning tool pivoted on the shaft means on an axis transverse to the axis of the pipe and adapted to engage the end of the pipe and to spin it outward as the spinning tool is rotated about the axis of the pipe while increasing the angle between it and the axis of the pipe.

2. The tool of claim 1 in which the means engaging the external surface of the pipe comprises a clamp.

3. The tool of claim 2 mating arcuate jaws of a toggle wrench.

4. The tool of claim 1 in which the arbor means is a cylindrical plug.

5. The tool of claim 4 in which the plug has an expansible split ring frictionally engaging the bore of the pipe to hold the plug in place prior to clamping.

6. The tool of claim 1 in which the spinning tool is of circular cross section.

7. The tool of claim 6 in which the outer surface of the spinning tool increases in diameter from its pivot.

8. The tool of claim 7 in which the outer surface of the spinning tool is concave in longitudinal section.

9. The tool of claim 1 in which the structure at one end is duplicated at the opposite end but with arbor means of a different size so the tool may be used to flare two sizes of pipe and the arbor means for one size may be used as a crank for rotating the spinning tool to flare a pipe of the other size.

10. The tool of claim 9 in which the arbor means at each end comprises a cylindrical plug.

11. The tool of claim 1 having an annular stop axially inward of the pivot for the spinning tool to stop the angle between the spinning tool and the axis of the pipe to control the finished flare.

12. The tool of claim 1 in which the spinning tool has a gage mark to be lined up with the end of the pipe so as to position the arbor means to insure the proper amount of free pipe for flaring.

13. A pipe flaring tool for thermo plastic pipe comprising arbor means adapted to be received in the bore of a pipe adjacent the pipe end to be flared, means engaging the external surface of the pipe opposite the arbor means and cooperating with the arbor means for clamping the intervening pipe wall therebetween while leaving the pipe end to be flared free, a spinning tool, means for supporting the tool for rotation relative to the pipe on its axis and for movement along said axis, said tool having a surface transverse to said axis adapted to engage successive local portions of said pipe end and deflect said local portions of said pipe end axially inward and radially outward of said axis relative to the portion of said pipe end adjacent said local portions and to form said pipe end into a continuous flare by relative rotation of the tool about and relative movement of the tool along said axis.

14. The tool of claim 13 in which the surfaces of the tool engaging local portions progressively increase in radial distance from said axis as the tool moves toward said pipe end.

15. A pipe flaring tool for thermoplastic pipe comprising means for holding the pipe while leaving the pipe end to be flared free, a spinning tool, means for supporting the tool for rotation relative to the pipe on its axis and for movement relative to the pipe along said axis, said tool having a surface transverse to said axis adapted to engage successive local portions of the end of the pipe and deflect said local portions axially inward and radially outward of said axis relative to the portions of said pipe end adjacent said local portions by relative rotation of the tool about said axis and relative movement along said axis.

References Cited UNITED STATES PATENTS 1,661,367 3/1928 Helminiak. 1,732,324 10/ 1929 Beardsley 93-1 2,303,061 11/1942 Parker .a 72316 J. SPENCER OVERHOLSER, Primary Examiner L. R. FRYE, Assistant Examiner US. Cl. X.R. 721l5, 316 

